CN111405952A - System and method for delivering material for printing three-dimensional (3D) objects - Google Patents

Abstract

A conveying system for conveying multiple layers of powder to a three-dimensional (3D) printing system for printing at least one 3D object, the conveying system comprising: a rotatable drum having a circular photosensitive outer surface, a hopper unit comprising a container for storing powder, wherein the hopper unit is configured to distribute the powder onto the photosensitive outer surface of the rotatable drum. The conveying system also includes a conveying unit comprising a movable conveying plate having a conductive outer surface, an engine for moving the conveying plate to a working chamber of the 3D printing system, one or more charging electrodes configured to charge the rotatable drum, and a charging unit configured to charge the conveying plate. The movable conveying unit is also configured to: electrically attract and successively attract the distributed multiple layers from the outer surface of the rotatable drum to its conductive outer surface; and transfer the attracted multiple layers to the working chamber by electrically repelling the attracted multiple layers into the working chamber.

Description

System and method for delivering materials for printing three-dimensional (3D) objects

cross reference

This application claims US Provisional Application Serial No. 62/582,327, filed November 7, 2017, and entitled "THREE DIMENSIONAL METAL PRINTINGSYSTEMS AND METHODS USING PHASE ARRAY COHERENT HIGH-POWER LASER" and filed on January 12, 2018 The benefit of US Application Serial No. 15/869,395, entitled "SYSTEMS AND METHODS FORDELIVERING MATERIALS FORPRINTING THREE DIMENSIONAL (3D) OBJECTS", each of which is hereby incorporated by reference in its entirety .

Field of Invention

The present invention relates generally to three-dimensional printing systems and methods, and in particular to systems and methods for transferring materials to three-dimensional printing systems.

Incorporated by reference

All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application.

Background of the Invention

Three-dimensional (3D) printing, also known as additive manufacturing (AM), is gaining popularity. As technology has advanced, different methods of forming 3D models through additive manufacturing techniques have been proposed. In general, additive manufacturing techniques use design information from 3D models from software such as computer-aided design (CAD) to convert into successive stacks of multiple thin cross-sections (quasi-two-dimensional). One of the common methods used for 3D printing is to use powder and solidify it into the desired shape. Examples of existing 3D printing methods and systems include, for example, Selective Laser Melting (SLM) or DMLS (Direct Laser Sintering of Metal Powders), which include high power density lasers for melting and fusing metal or polymer powders together.

In recent years, electrophotographic methods and systems used in two-dimensional (2D) printing have been implemented in 3D printing methods. According to prior art (2D) printing, an electrophotographic system includes a conductive support roller coated with a photoconductive material, wherein the electrostatic latent image is generated by uniform charging and then image-wise exposure of the photoconductive layer by a light source. Forming. The electrostatic latent image is then moved to a developing station where toner is applied to the uncharged areas of the photoconductive insulator to form a visible image. The formed toner image is then transferred to a substrate (eg, printing paper) and adhered to the substrate using heat or pressure.

An example of an additive manufacturing system for printing three-dimensional parts using electrophotography is described in US Patent No. 8,488,994, entitled "Electrophotography-based additive manufacturing system with transfer-medium service loops." The additive manufacturing system includes: a rotatable photoconductor member; a development station configured to develop a layer of material on a surface of the rotatable photoconductor member; a rotatable transfer medium configured to transfer from a rotatable A surface of the rotating photoconductor member receives the developer layer; and a platen configured to receive the developer layer from the rotatable transfer medium in a layer-by-layer fashion. The additive manufacturing system also includes a plurality of service loops configured to move the portions of the rotatable transfer medium at different linear speeds while maintaining a net spin rate of full rotation of the rotatable transfer medium substantially constant status.

FIG. 1 illustrates a selective laser melting (SLM) system 100 for dispensing material in powder form in a 3D printing system according to the prior art. The system 100 includes a melting vessel 101 , a powder vessel 102 and a laser head 103 configured to emit a laser beam for melting an image of a powder layer dispensed from the powder vessel 102 to the melting vessel 101 . Specifically, in operation, once the melting process of a single layer (eg, the top layer) is complete, the carrier plate 106 (holding the powder 104 and the print model 105 ) moves downward while the carrier plate 108 moves upward and the rollers 109 or plates remove the powder layer Dispense from powder container 102 to container 101 to be melted by laser head 103 .

SUMMARY OF THE INVENTION

According to a first embodiment of the present invention, there is provided a delivery system for delivering a plurality of layers of powder to a three-dimensional (3D) printing system for printing at least one 3D object, the delivery system comprising : a rotatable drum having a circular photosensitive outer surface; a hopper unit comprising a container for storing the powder, wherein the hopper unit is configured to dispense the powder to the the photosensitive outer surface of the rotatable drum; a conveying unit comprising a movable conveying plate having a conductive outer surface, the conveying unit being connectable to the conveying plate for moving the conveying plate to the 3D of an engine of a studio of a printing system; one or more charging electrodes configured to charge the rotatable drum; a charging unit configured to charge the rotatable drum and wherein the movable conveying unit is further configured to: electrically and sequentially attract the plurality of layers from the outer surface of the rotatable drum to the conductive outer surface thereof; The layers are electrically repelled into the working chamber while the attracted layers are transferred to the working chamber.

In some embodiments, the conductive outer surface of the delivery plate is coated with one or more layers of insulating material.

In many embodiments, the powder includes a non-conductive powder material or a conductive powder material.

In many embodiments, the hopper unit includes one or more layers of insulating material.

In many embodiments, the rotatable drum includes a cleaning unit configured to clean the photosensitive outer surface of the rotatable drum.

In many embodiments, the conveying unit includes a cleaning unit configured to clean the surface of the conveying plate.

In many embodiments, the transport system includes: a plurality of rotatable drums having a circular photosensitive outer surface for respectively receiving the plurality of layers, wherein the plurality of rotatable drums Each of the drums includes: a hopper unit, wherein each hopper unit includes the container for storing the powder or one or more other types of powder; a cleaning unit configured to separately cleaning the photosensitive outer surface; one or more charging electrodes configured to apply an electrostatic charge to each respective rotatable drum of the plurality of rotatable drums; energy scanning unit, wherein each energy unit includes an energy source configured to selectively emit a light beam towards the respective photosensitive outer surface for causing all the the photosensitive outer surface discharge; and wherein the movable conveyor plate is configured to sequentially attract and electrically attract the plurality of layers from the plurality of rotatable drums to form a powder layer at the plate outer surface, and The powder layer is transferred to the working chamber in a layer-by-layer manner by electrically repelling the powder layer into the working chamber.

In many embodiments, the working chamber includes: a work surface configured to receive the plurality of layers and to be stepped down; and an energy head for melting the plurality of layers.

In many embodiments, the energy head is a laser head configured to, based on CAD cross-sectional data of a selected cross-sectional area of the model, in such a way that each powder layer is affixed to the layer below, A focused laser beam is applied to a given area of each of the plurality of layers corresponding to the selected cross-sectional area of the model molding the 3D object.

In many embodiments, the 3D printing system is a compression system.

In many embodiments, the compression system includes: a container having a cavity; a receiving surface for receiving a plurality of layers from the transport plate; and a top press, the top press Used to compress the received multiple layers and form a dense powder layer.

In many embodiments, the dense powder layer is sintered.

In many embodiments, one of the dense powder layers includes material that may not be sintered.

According to a second aspect of the present invention, there is provided a method for delivering multiple layers of powder to a 3D printing system for generating one or more 3D objects, the method comprising: rotating a photosensitive at least one roller of the surface; charging the at least one rotating roller for receiving the plurality of layers from the hopper unit at the photosensitive surface; moving the conveying unit tangentially to the working chamber relative to the at least one roller , wherein the conveying unit comprises a movable conveying plate having a flat conductive outer surface; charging the conveying plate for successively attracting the plurality of layers from the photosensitive surface of the at least one drum; The transfer plate is positioned above or near the working chamber, switching the electrical polarity of the transfer plate for repelling the layers into the working chamber.

In many embodiments, the method includes melting the repelled plurality of layers by an energy cell for use in creating the one or more 3D objects.

In many embodiments, the method includes compressing each of the repelling plurality of layers.

In many embodiments, the method includes sintering the compressed plurality of layers.

In many embodiments, the plurality of layers include a first type of powder material and a second type of powder material, wherein the second type of powder material has a higher sintering than the first type of powder material temperature.

In many embodiments, the method includes moving the conveyor unit at a rate synchronized with the speed of the rotatable drum.

According to a third embodiment of the present invention, there is provided a conveying system for conveying multiple layers of powder for printing at least one 3D object, the conveying system comprising: a plurality of rotatable drums, wherein , each rotatable drum in the plurality of rotatable drums has a photosensitive outer surface for respectively receiving the plurality of layers, and wherein each rotatable drum in the plurality of rotatable drums comprises: a hopper unit, wherein the hopper unit includes a container for storing powder; a cleaning unit configured to clean the respective photosensitive outer surfaces of the plurality of rotatable drums; one or more charging electrodes , the one or more charging electrodes are configured to apply an electrostatic charge to the rotatable drum, respectively; a scanning energy unit, wherein the scanning energy unit includes an energy source configured to be selectively directed toward Respective photosensitive outer surfaces of the plurality of rotatable drums emit light beams for discharging the photosensitive outer surfaces according to a predefined image structure of the at least one 3D object; a conveying unit, the conveying unit comprising a conductive outer surface; a movable conveying plate of the surface, the conveying unit being connectable to an engine for moving the conveying plate to the studio of the 3D printing system; and a charging unit configured to supply the conveying plate charging; and wherein the movable conveying plate is configured to sequentially attract and electrically attract the plurality of layers from the plurality of rotatable drums to form a powder layer at the outer surface of the plate, and by applying The powder layer is electrically repelled into the working chamber to transfer the powder layer to the working chamber in a layer-by-layer fashion.

Brief Description of Drawings

A better understanding of the features and advantages of the present disclosure will be obtained by reference to the following detailed description, which sets forth illustrative embodiments utilizing the principles of the embodiments of the present disclosure, and the accompanying drawings.

Figure 1 illustrates a system for printing 3D models using powder layers according to the prior art;

2A is a schematic diagram illustrating a delivery system configured to deliver one or more materials to a working chamber of a three-dimensional printing unit using electrostatic methods, according to an embodiment;

2B is a schematic diagram illustrating a delivery system including a scanning unit, according to an embodiment;

2C is a schematic diagram illustrating a multiple material delivery system for printing 3D objects made from multiple types of materials, according to an embodiment;

2D is a schematic diagram illustrating a hopper unit configured to feed material to a rotating drum, according to an embodiment;

3 is a high-level block diagram schematically illustrating elements, including software elements such as operational commands and hardware elements of a delivery system, according to an embodiment;

4A shows a flow diagram of a method for delivering one or more materials using an electrophotographic method, according to an embodiment;

4B is a schematic diagram illustrating a delivery plate at various stages, according to an embodiment;

4C is a schematic diagram illustrating a delivery system in a home position, according to an embodiment;

5 is a schematic diagram illustrating a multi-material delivery system including a single cylinder configured to deliver a plurality of materials to a three-dimensional printing system using electrophotographic methods, according to an embodiment;

Figure 6 shows a schematic diagram of a multi-material delivery system according to another embodiment;

7 shows a schematic diagram of a multi-material delivery system using vacuum, according to an embodiment;

FIG. 8 shows a schematic diagram of a cross-section of the conveyor plate of FIG. 7, according to an embodiment;

9A shows a flowchart of a method for conveying a plurality of materials using a vacuum method, according to an embodiment;

9B illustrates a schematic top view of the state of the delivery system at each delivery step, according to an embodiment;

10 is a cross-sectional view of a molding system 100 according to the prior art;

11 is a schematic diagram illustrating a system for generating 3D objects, according to an embodiment;

12 illustrates a flow diagram of a method for delivering at least two materials to a compression system and generating one or more 3D objects, according to an embodiment; and

13 illustrates a computer system suitable for use in conjunction with methods and apparatus according to some embodiments of the present disclosure.

Detailed description of the invention

In the following description, various aspects of the present invention will be described. For purposes of explanation, specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent to those skilled in the art that other embodiments of the present invention vary in detail without affecting the essence of the present invention. Accordingly, the invention is not to be limited by what is shown in the drawings and described in the specification, but as indicated in the appended claims, with the proper scope to be determined only by the broadest interpretation of such claims .

As used herein, similar characters refer to similar elements.

Thus, as used herein, the term "photoconductive" may also refer to photosensitivity.

The configurations disclosed herein can be combined in one or more of a variety of ways to provide improved 3D printing delivery methods, systems and apparatus. One or more components of the configurations disclosed herein may be combined with each other in a variety of ways.

According to some embodiments, methods and systems are provided for printing a 3D model comprising using electrostatic methods to transfer a single type of powder to a studio of a 3D printing system.

According to other embodiments, methods and systems are provided for transferring multiple layers in powder form, wherein the multiple layers may include two or more materials (eg, different powder materials) for printing at least one 3D object. The conveying system includes: a rotatable drum having, for example, a circular photosensitive outer surface; a hopper unit including a container for storing one or more materials, wherein the hopper unit is configured to transfer powder Dispensing on the photosensitive outer surface of the rotatable drum; a conveying unit comprising a movable conveying plate having, for example, a flat conductive outer surface which can be isolated, and wherein the conveying unit is connectable for moving the conveying plate to the work an engine of the chamber; one or more charging electrodes configured to apply an electrostatic charge to the rotatable drum and the movable conveying unit; and wherein the movable conveying unit is further configured to: The rotatable drum outer surface electrically attracts and sequentially attracts a plurality of dispensed material layers to its photosensitive outer surface; and transfers the attracted material layers to the working chamber of the 3D printing system in a layer-by-layer manner by electrically repelling the material layers into the working chamber .

According to another embodiment, a method and system for printing a 3D model including using a vacuum suction method to deliver powder to a studio is provided.

In some cases, the powder is coated with or contains a dielectric material or liquid. The dielectric material may include nanoparticles made of, for example, polyester or wax contained in a nanocomposite or coating.

2A illustrates a delivery system 200 configured to deliver one or more materials to a working chamber 290 of a three-dimensional printing unit using electrostatic methods, according to an embodiment. The system 200 includes a rotating photoconductive or photosensitive member, such as a photoconductive or photosensitive drum 214, which is configured to be rotated by one or more motors 201 according to a predefined rotational speed, eg, counterclockwise, and is passed from a hopper. Unit 213 electrically attracts material to receive one or more layers of material (eg, in powder form). The system 200 also includes a conveying unit 205 that includes a conveying plate 218 , such as a movable conveying plate configured to move and attract material from the photoconductive drum 214 . Additionally, the delivery plate 218 is configured to deliver the attracted layer or layers of material to the working chamber 290 where the material is melted by an energy source such as a laser source 295, for example. Alternatively, the delivered layer or layers of material may be pressed according to known 3D printing or compression methods for forming 3D models.

According to some embodiments, drum 214 is configured to rotate about axis 208, for example. The shaft 208 is correspondingly connected to a drive motor 201 which is configured to rotate the shaft 208 counterclockwise. In some cases, drum 214 may rotate at a constant rate.

Roller 214 may have a cylindrical shape or other shapes, and may include or may be made of conductive material (such as copper, aluminum, etc.). Roller 214 includes a surface, such as a circular photosensitive or photoconductive outer surface 216, that is configured to be uniformly electrostatically charged by a charging device (eg, by charging unit 219).

In some cases, surface 216 is a thin film extending around the circumferential surface of conductive roller 214 and is derived from one or more photoconductive materials, such as amorphous silicon, selenium, and the like. Surface 216 is configured to utilize electrostatic attraction to receive one or more materials in the form of, for example, dispensed powder from hopper unit 213 positioned, for example, at the right side of drum 214 .

According to some embodiments, the hopper unit 213 includes a container or cassette 209 for storing one or more materials, eg in the form of powder 207 , and one or more channels for releasing the powder 207 attracted by the charged rotating surface 216 . According to some embodiments, the hopper unit 213 includes a drum 221 configured to receive powder from the container 209 and rotate while the powder 207 is electrically adhered to the uncharged areas on the drum 214 .

In some cases, the hopper unit 213 may include a developer blade 257 configured to charge the powder. Specifically, the developer blade 257 may be attached on the top of the hopper roller 221 . The developer blade 257 may comprise, for example, a stainless steel layer with chrome or the like.

According to some embodiments, the powder 207 may be charged during its rubbing with the developer blade 257 and as the powder 207 is dispensed from the container 209 and adhered (eg, attracted) to the drum, the powder is rubbed and carried by the developer blade Static electricity. Since the dispensed powder has the same charge as the charged areas in the drum 216 , the powder 207 is removed from the charged areas and adheres to the drum only in the areas exposed by the energy scanning unit 270 .

In some embodiments, the powder may comprise or may be made of a conductive material coated with an insulating material.

The drum 214 may include cleaning units 217 on its radial surface adjacent to the rotating drum 214 for removing particles from the surface 216 from previous dispensing cycles. In some cases, adjacent to cleaning unit 217 , system 200 includes a discharger unit 223 for discharging the drum, eg, by directing a beam of light toward surface 216 . According to some embodiments, charging unit 219 may include a roller charge (eg, corona wires, scorotrons, charge rollers, and other electrostatic charges) configured to charge rotating drum and/or surface 216 equipment).

According to some embodiments, the conveyor plate 218 is configured to move in a direction 232 toward the working chamber 290 using one or more engines, such as along a track. In some cases, the delivery plate 218 is connected to an actuator, such as a linear actuator or linear piston. In some cases, the delivery plate 218 may be connected to a rotating system, such as a motor configured to convert axial motion of the motor to rotational motion through a gear drive or through a screw assembly.

According to some embodiments, the delivery plate 218 is positioned and moved above the drum 214 in the direction 232 of the arrow tangent to the drum 214 (eg, the X axis parallel to the X-Y-Z axis) and toward the working chamber 290 . The rotational speed of the drum 216 and the speed of the conveyor plate 218 are synchronized, for example, by the processor 250, for receiving the dispensed material once the conveyor plate 218 is positioned above or below the drum 216, and for maintaining a neat and straight layer .

In some cases, the delivery plate 218 may have a rectangular shape or other shape, and may be made of a conductive material such as copper, aluminum, and the like. According to an embodiment, the delivery plate 218 is made of a conductive material so that it can be charged by an electric charger 237 which will pull the powder layer 264 from the drum 214 . In some cases, the delivery plate may include a conductive flat outer surface made of a conductive material such as copper, aluminum, and the like. In some cases, the transport plate may have a thickness of several centimeters, such as 1-5 microns.

According to some embodiments, the delivery plate 218 may include one or more layers of insulating material. In particular, where powder materials made of conductive materials are used to generate 3D objects, the bottom portion of the delivery plate 218 (eg, the outer surface 203 of the delivery plate that is in contact with the powder) may include insulation of, eg, 1-20 microns A thin layer 279 of material that is configured to prevent the charge of the powder from being transferred to the delivery plate.

According to some embodiments, delivery plate 218 includes a cleaning unit 247 , eg, at a distal end (eg, the left distal end) below delivery plate 218 , for cleaning previous delivery cycles from surface 213 Material particles left behind.

According to some embodiments, the working chamber 290 includes a carrier plate 291 (for receiving the powder layer) configured to lift up or down and receive the material layer from the delivery plate.

According to some embodiments, the delivery system 200 is configured to dispense material in powder form from the hopper unit to the surface of the drum without the use of a scanning or energy device, such as a laser or imaging device, to selectively target the corresponding photosensitive exterior of the drum The surface emits a light beam for discharging the photosensitive outer surface, thereby enhancing and accelerating the powder delivery process.

According to some embodiments, energy source 295 may be a laser source, such as a fiber phase array coherent high-power laser configured to atomize one or more hot melt materials (such as material layer 294) to create layers of 3D objects. Alternatively, the known electron beam melting (EBM) method is used for the image in the fused layer.

In operation, a plurality of powder layers (eg, homogenous layers) are sequentially dispensed from the hopper unit 213 over the entire or substantially the entire circumferential surface 216 of the drum 214 . At a next step, the transfer plate 218 may be charged with an opposite charge to that of the powder, eg, positively charged by the charger 237 for attracting the powder from the rotating surface 216 . After the charging phase, the transport plate 218 begins to move toward the working chamber 290 (eg, horizontally, eg, along the X-axis). When the conveyor plate is positioned above or partially above the drum (eg, tangentially or close to the rotating drum), the powder layer of material is electrically attracted to the conveyor plate surface 203 . At the next step, the transport plate 218 continues to move from the rotating drum to the working chamber 290, and once the transport plate 218 is above the working chamber 290, the charger 237 switches the electrical polarity of the transport plate. For example, the charger 237 discharges the charge of the board and charges the board with an opposite charge to that which has been previously charged. Since both the powder and the plate now carry the same polarity, the powder and the plate are electrically repelled and fall to the working chamber 290 .

Thus, at each delivery cycle, the powder layer is repelled from the delivery plate 218 and received at the working chamber 290 . Afterwards, each received powder layer is for example melted separately by an energy unit, or compressed by pressing means according to the corresponding 3D cross-sectional image of the 3D object image.

It is emphasized that, according to some embodiments, the final structure or cross-section of the 3D object is formed at the working chamber 290 and not at the conveyor plate or roller.

FIG. 2B is a schematic diagram illustrating system 210 according to another embodiment. The system 210 presents all the elements of the aforementioned system 200, but also includes an energy scanning unit 270 including, for example, an energy source 241, such as a laser source, in communication with the processor unit 250 for scanning according to the 3D object The predefined image structure to control the scanning unit 270. According to the processor unit 250, the scanning unit 270 is configured to selectively emit a light beam 243 towards the electrostatically charged surface 216 via the mirror unit 251 when the drum 214 is rotated (eg counter-clockwise) for use in rendering the surface according to a predefined image structure 216 discharge. The location of the selective discharge causes the powder to fall out of the container tube and be electrically attached to the surface 216, forming a layer according to the model cross-section of the 3D CAD model. The dispensed powder 264 is rotated towards the charged delivery plate 218 which attracts and delivers the dispensed powder 216 to the working chamber 290 .

According to some embodiments, the energy source may be a scanning laser (eg, gas or solid state laser) light source, light emitting diode (LED) array exposure equipment, and other exposure equipment conventionally used in 2D electrophotographic systems. In an alternative embodiment, suitable equipment for the energy source includes an ion deposition system configured to selectively deposit charged ions or electrons directly onto the drum surface 216 to form a latent image charge pattern).

FIG. 2C shows a multi-material delivery system 260 for printing 3D objects 293 made of various types of materials, according to an embodiment. The delivery system 260 is configured to deliver multiple materials, such as different types of materials 207A, 207B, 207C in powder form, to the working chamber 290 simultaneously, for example. The multi-material conveying system 260 includes at least two rollers, eg, three rollers 214A, 214B, and 214C. According to some embodiments, each drum includes a unit as illustrated in Figure 2B. Specifically, the three drums 214A, 214B and 214C respectively include three hopper units 213A, 213B and 213C (which include, for example, different powder materials 207A, 207B and 207C), three cleaning units, three discharger units 219A, 219B , 219C and three scanning units 270A, 270B and 270C. The delivery system 260 also includes one or more control units 280 that include one or more processors, such as a microprocessor-based engine control system and/or a digitally controlled processor system , which is configured to operate multiple transport system 260 components in a synchronized manner based on print instructions received from host computer 282 . Host computer 282 is one or more computer-based systems configured to communicate with controller 280 to provide delivery instructions (and other operational information). In some cases, the controller may communicate with the printer controller 283 for scheduling and/or synchronizing the delivery of powder to the working chamber. For example, host computer 282 may pass information related to the desired 3D model to processing controllers 280 and 283, so controller 280 schedules controller 283 on each cycle of the transport layer, allowing system 260 to rapidly operate in a layer-by-layer fashion Delivered to working vessel 290.

In some cases, materials 207A, 207B, and 207C may be selected from the group consisting of titanium, aluminum, stainless steel, or nickel-based superalloys.

2D is a schematic diagram illustrating a hopper unit 273 configured to feed material 207 (eg, conductive material in the form of powder particles) to rotating drum 216, according to some embodiments. The hopper unit 273 includes a container 276 shaped as a box or cube for storing the material 207 . The container 276 may be made of insulating material such as ABS plastic, ceramic or known insulating materials. In other embodiments, the container may include one or more insulating materials or may be internally coated with one or more insulating materials, such as at one or more contact areas inside the container, to prevent charge scattering from charged materials.

In operation, material 207 may be charged to a high potential, eg, several hundred thousand volts (eg, 5,000-200,000 volts), eg, by one or more electrode units 277 located at the bottom of container 276 . In some cases, all or substantially all of the powder particles 207 carry the same electrical charge and thus repel each other, thereby forming a particle cloud of powder particles 207 . When the loaded powder reaches the drum 216, it adheres to the area marked by the laser scanner in a similar manner to existing methods.

According to some embodiments, the powder particles 207 may be coated with a thin dielectric material having a thickness ranging, for example, from 1 micron to 5 microns. Alternatively, when the nanoparticles have dielectric properties, the powder particles 207 may include nanoparticles attached to the outer surface of the powder particles. In some cases, the powder is charged. In some cases, individual particles of the powder may have a size of 3 microns to 100 microns. The nanoparticle coating provides electrostatic properties to the powder and may evaporate during the melting process. Nanoparticles can be attached to the powder 207 .

In some cases, the powder particles may be non-conductive materials.

3 is a high-level block diagram schematically illustrating elements, including software elements such as operational commands and hardware elements of the delivery system 300, according to an embodiment. System 300 includes a computing unit including one or more computer-based systems configured to communicate with controller 301 to provide delivery and printing instructions 317 (as well as other operational information).

Instructions 317 for implementing the delivery and printing process of the example method 400 may be stored in a non-transitory computer-readable storage medium, such as a computing unit. When executed by a computing system, the instructions may cause the computing system to perform a method of operating a transport and printing system based on predefined data. In some embodiments, a non-transitory computer-readable storage medium is one or more physical devices used to store data or programs on a temporary or permanent basis. For example, non-transitory computer-readable storage media include flash memory, dynamic random access memory (DRAM), CD-ROMs, DVDs, flash memory devices, magnetic disk drives, tape drives, optical disk drives, and cloud computing-based storage devices.

A computing system suitable for use in conjunction with methods and apparatus according to some embodiments of the present disclosure is illustrated in FIG. 13 .

The controller is configured to receive 3D data 311 including information such as a three-dimensional computerized model (eg, STL [Standard Template Library] format file) converted into, for example, a plurality of thin cross-sections (quasi-two-dimensional), wherein Each cross-section includes multiple layers of images for each respective powder material. For example, for a 3D model that includes three types of powder materials, three cross-sectional images will be provided for each layer. The controller analyzes the received information for providing commands 302-307 for operating the delivery system, preferably in the following order. Note, however, that commands can operate in a different order.

Commands 302 include the following instructions for operating the units of each drum 214A, 214B and 214C synchronously, for example:

operate roller cleaning units 217A, 217B and 217C;

operate electrostatic charging units 219A, 219B, and 219C; and

Hopper units 213A, 213B and 213C are operated.

Commands 303 include one or more instructions for operating the drum engine. In some cases, commands 303 include speed control commands and position commands. For example, the controller may give commands to rotate the drum to the point where it is desired to attach the powder to the drum so that the powder adheres to the receiver plate 218 in the position required for precise layer deposition in the working chamber 290 .

Commands 304 include data for directing the energy scanning unit to selected points (eg, in pixels) on each cylinder surface to form a desired image by, for example, electrophotographically exposing selected points on the cylinder surface. The data may include sliced 2D images of the 3D model for each drum. For example, Figure 2C shows a sample cross-sectional 2D image of a 3D object 293 created, for example, by fusing multiple layers 297 comprising three different materials 207A, 207B, and 207C.

Each of the commands 302-304 operates the drum and corresponding scanning unit.

Commands 305 include one or more instructions for operating delivery plate 218 for receiving dispensed powder from drums 214A, 214B, and 214C and delivering the received powder for melting at working chamber 290 or suppress. Command 305 may include the following instructions:

Move the conveying plate to the relevant position (eg P0, P1...P5);

Charge the conveyor plate;

discharge the conveying plate;

The cleaning unit 247 of the conveying plate is operated.

Commands 306 include instructions for controlling and synchronizing the position and speed of transport plate 218 and carrier plate 291 . For example, the instructions include drums engine roaring speed synchronized with the lift rate of the carrier plate engine.

Command 307 includes data in the form of, eg, one or more images of sliced layers of a 3D object (eg, object 293 ) for selectively melting the powder layer at working vessel 290 . And an energy unit 295 (or pressing unit) that operates the working chamber for melting the delivered powder.

4A shows a flowchart of a method 400 for delivering one or more materials using electrophotographic and electrostatic methods, according to an embodiment. The method involves a conveying system comprising three rollers, but may also involve any other conveying system comprising fewer or more than three rollers.

At steps 412-414, the system unit is activated. The activation phase includes the following steps: At step 412, the cleaning unit, electrostatic charging unit and hopper unit of each drum are activated. At step 414, the motor 201 of each respective drum is activated for rotating each drum according to a predefined speed. At step 416 , the unit is moved to the “home” position, ready to transfer one or more types of materials to the working chamber 290 . For example, FIG. 4C illustrates a perspective view of 3D printing system 400 in a "home" position ready to deliver three types of materials (eg, powders A, B, and C) to studio 490 . The working chamber 290 may be located on the distal left side of the 3D printing system 400 near the left side of the delivery system 481, and thus in the "home" position, the delivery plate 218 is located on the distal right side near the right side of the delivery system 481. Thus, the carrier plate 406 is positioned at the upper level of the working chamber 490 for receiving the first powder layer from the delivery system 481 .

At the next stage as illustrated at steps 422-428, the tier allocation cycle begins. At step 422, data is transmitted from the controller to the corresponding scan unit of each cylinder. The data includes 3D CAD file data sliced into 2D images of each layer of each material for use in generating images of the discharge areas on the surface of each drum to electrically charge the material accordingly based on the data Attached to each roller. At step 424, data (eg, image fusion data) is transmitted from the controller to the fusion unit. The data includes information in the form of, for example, one or more images of sliced layers of the 3D part for selectively melting the powder layers at the working vessel. At step 426, the delivery plate 218 is charged, such as being positively charged by, for example, the charger 237, for attracting the dispensed powder from the rotating surfaces 216A, 216B, and 216C of the drum.

At the next step, the charging units 241A, 241B and 241C are operated sequentially for electrostatically charging the surfaces, respectively, as the drum rotates (eg, counterclockwise), for attracting material from the hopper unit. Accordingly, the delivery plate 218 is moved forward in the direction of arrow 232 towards the drum and over the drum (eg, tangentially) for electrostatically attracting the powder layer from the rotating drum. Specifically, at step 432, the energy scanning unit 270A is activated to emit a beam of light to the drum 214A for exposing selected areas in the drum surface, and at step 433, the material 207A from the hopper unit is thus attracted to the drum exposed areas on the surface. At step 434 , the transport plate is moved toward and over the first roller 214A for attracting material from the surface of the roller at step 435 . For example, as illustrated in Figure 4B, the transfer plate moves from point P1 to point P2, which is located above the first roller 214A a distance L2 from P0, and attracts material 207A from the roller 214A to the transfer plate surface. P1 can be defined as the starting powder image point on the conveyor plate.

According to some embodiments, the conveying plate speed is:

Speed of V-plate = N*D*PI (M/min)

in:

D-diameter of outer drum (M)

N – the rotational speed of the drum (RPM)

At step 436, scanning unit 240B emits a light beam to drum 214B for exposing selected areas in drum surface B and for attracting material from the surface of the drum at step 437. At step 438, the transport plate continues to move towards the second roller B for collecting the second material. Specifically, as illustrated in Figure 4B, the conveying plate moves from point P2 to point P3, which is located above the second roller 214B at a distance L3 from P0, and attracts material 207B from the roller 214B to the surface of the conveying plate 218. At step 439, the material 207B from the hopper unit 209B is thus drawn to the exposed areas on the drum surface. At step 442, scanning unit 270C emits light beam 443C to drum 214C for exposing selected areas in drum surface C and for attracting material from the surface of the drum at step 443. At step 444 , the transport plate 218 continues to move towards the third roller C for collecting the third material 207C at step 445 . Specifically, as illustrated in Figure 4B, the distal end of the transport plate moves from point P3 toward point P4, which is located above third roller 214C a distance L4 from P0, and attracts material 207C from roller 214C to the Conveyor plate surface.

In some cases, powder may be simultaneously delivered from one or more rollers to receiver plate 218 in order to reduce delivery process time. For example, step 439 may operate while step 435 is still in operation, and correspondingly step 445 may operate while both steps 435 and 439 are still in operation.

After all layers of material are gathered by the conveyor plate 218 from the respective rollers, at step 450 the conveyor plate 218 is moved continuously from point P4 towards the work container 290 and point P1 of the conveyor plate is positioned at point P5, thus attached to A material image of the bottom portion of the transport plate is placed over the working chamber (eg, covering the working chamber). At step 460 , the transport plate 218 is discharged and charged with the opposite sign (eg, switching the electrical polarity of the transport plate), and thus, at step 462 , the layer of material is electrically repelled from the transport plate 218 and distributed to the carrier plate 206 superior. At step 470 the cleaning unit is activated, and at step 472 the transport plate moves from point P5 back to point P0 (the original position (home position). At step 480, the dispensed powder layer is melted by the energy cell laser head, and at step 482, the carrier plate 291 (holding the currently melted powder) reduces the layer thickness S on the vertical (Y) axis.

At step 490, a binary decision may be made regarding the index number of the allocated layer. If it is the last layer (eg, all 3D object layers were transferred and fused at the studio), the printing process is complete, and at step 492 the carrier lift is raised back to the maximum of the studio 490 upper level. If it is not the last layer, the process continues at step 416 to deliver the next layer.

5 illustrates a multi-material delivery system 500 configured to deliver multiple materials to a three-dimensional printing system using electrophotographic methods, according to an embodiment. System 500 includes a single photoconductive roller 514 configured to rotate by one or more motors according to a predefined rotational speed, eg, counterclockwise. In some cases, the drum rotates at a constant rate. The drum may have a cylindrical shape or other shapes, and may include or may be made of a conductive material, such as copper, aluminum, organic photoconductors made of N-vinylcarbazole (eg, organic monomers), and the like. Roller 514 includes a surface such as photoconductive surface 516 coated with one or more photoconductive materials (such as selenium, etc.) and configured to be electrostatically charged by a charging device (eg, by electrostatic charger 523).

According to some embodiments, the system 500 includes a plurality of hopper units for supplying different types of materials to be electrically attached to the drum surface 516 . The system 500 also includes a plurality of corresponding scanning units for discharging selective locations on the surface according to a predefined image structure.

Specifically, according to some embodiments, the system includes four hopper units 513A, 513B, 513C, and 513D positioned about the circumferential surface 516 for covering the drum's surface and corresponding scanning units. Peripherally, the corresponding scanning unit is used to mark selected locations on the drum surface 516. More specifically, each of the hopper units 513A, 513B, 513C, and 513D respectively includes a container for correspondingly storing material (eg, four different types of powder materials) and a container for releasing powder attracted by the charged rotating surface. one or more channels. According to some embodiments, each of the hopper units 513A, 513B, 513C, and 513D includes a drum configured to receive powder from the container and in an uncharged area where the powder is electrically attached to the drum 514 (eg, according to a laser mark) and rotate while repelling the charged areas on the drum.

The cylinder 514 may include on its radial surface a cleaning unit 517 in communication with the rotating cylinder for removing particles from the cylinder 514 from previous printing cycles. In some cases, near the cleaning unit 517, the system 500 may include a discharger/charger unit 523 (eg, corona wire, corotron, charging rollers, and other electrostatic charging devices).

In many embodiments, the principle of operation of the delivery system includes one or more of the following attributes. While the discharger/charger unit 523 charges the drum, the drum 514 rotates. At the next step, the drum is scanned by a first scanning unit, such as scanning unit 540A, by emitting a light beam (eg, a laser beam) that creates an image on the drum. According to the image, when the laser hits the drum, specific areas in the drum are discharged. After the drum is charged, the first hopper unit 513A comprising, for example, the drum with negatively charged powder rotates while the powder portion 564 of the first type of material is electrically attached to the uncharged areas on the drum 514 (eg, according to laser marking) and Repel with negatively charged areas on the roller. At the next step, as the drum rotates in the direction of arrow 501 , the scanning unit 540B emits light, eg, sequentially, towards the drum, for electrically attaching the second type of powder portion 567 . Thus, the third type of powder portion 569 and the fourth type of powder portion 571 are electrically attached to the surface by the energy scanner units 540C and 540D. At the next step, eg when the first rotation cycle is complete, eg a positively charged delivery plate 531 approaches the drum (eg moves tangentially upward relative to the drum 514) for receiving the dispensed powder portions 564, 567, 569 and 571 and transfer them in the direction of arrow 511 towards working vessel 590 for generating a first powder layer comprising various materials such as materials A, B, C and D.

FIG. 6 shows a schematic diagram of a multi-material delivery system 600 according to another embodiment. Delivery system 600 includes a delivery plate, such as photoconductive plate 618 having photoconductive surface 622 configured to directly attract and deliver various materials, eg, in powder form, to working chamber 690 . The conveyor plate 618 can be moved in the direction of arrow 625 using one or more engines, such as linear actuators 639, for activating and moving the conveyor plate at a predefined speed for collecting materials and conveying them to Studio 690.

According to some embodiments, the system 600 includes a plurality of hopper units and scanning units, such as the unit shown in FIG. 2C , located below the conveyor plate 618 . For example, system 600 may include three hopper units 613A, 613B, and 613C for supplying three different types of materials (eg, in powder form) to be electrically attached to surface 622 . The system also includes corresponding scanning units, eg three scanning units 670A, 670B and 670C, for emitting light beams and discharging selective locations on the surface according to predefined image structures.

The system 600 also includes a cleaning unit 617 located below the right distal end of the transport plate 618 for removing particles from the transport plate 618 from previous printing cycles. In some cases, near the cleaning unit 617, the system 600 may include a discharger/charger unit 623 (eg, corona wire, corotron, charging rollers, and other electrostatic charging devices).

In many embodiments, the principle of operation of the delivery system includes one or more of the following attributes. The transport plate 618 is charged by the charger 623 and moves in the direction of arrow 625 to and over the first scanning unit 670A, which scans the bottom surface 622 of the transport plate 618 by emitting a light beam (eg, a laser beam) The light beam creates an image on a portion of the desired area on the bottom surface 622 of the delivery plate (eg, discharges the selected area). When the beam hits the surface 622, certain areas of the surface 622 are discharged and thus the first type of material is electrically attracted from the hopper unit 613A and is electrically attached to the uncharged areas on the surface 622. At the next step, the transport plate 618 continues to move to the second scanning unit 670B, which emits light toward the surface 622 for the electrical attachment of the second type of material. Thus, the third type of material is electrically attached to the surface 622 from the hopper unit 613C by the third scanning unit 670C, which completes the formation of a powder layer image 672 including the three types of material attached to the bottom of the surface 622 . At the next step, the transfer plate 618 is moved to the working chamber 690, and once the plate 618 is directly above the working chamber 690, the transfer plate 618 is charged with the opposite sign, eg, by a power supply unit (eg, the discharger unit 669), and thus, The powder bed image 672 is electrically repelled from the transport plate 618 to the working plate 601 of the working chamber 690 . At the end of the cycle, the dispensed layer is melted, for example, and the transport plate 618 is moved back for transporting the next layer of the 3D object. According to some embodiments, cleaning device 617 removes particles left over from previous printing cycles as transport plate 618 moves back.

FIG. 7 shows a schematic diagram of a multi-material delivery system 700 according to an embodiment. The system 700 includes a transport plate 720 configured to attract and hold one or more materials, eg, at a bottom 722 of the transport plate, according to a predefined slice 2D image of the 3D object. The system 700 utilizes a vacuum method for receiving, holding, and transferring the received material to the working chamber. Specifically, the delivery plate 720 includes a sealed cavity 745 and an inlet tube 728, such as a vacuum tube or suction air tube, for connecting the delivery plate 720 to the pump 730, which is used to draw air from the sealed cavity 745, thereby forming a connection between the inside of the cavity and the outside low pressure compared to the pressure and creates a vacuum sealed chamber 745. System 700 also includes sealing material 750 for covering and sealing the bottom of delivery plate 720 . In some embodiments, the system 700 includes an automatic sealing tape roller 752 for rolling, storing, and attaching the sealing material. The automatic sealing belt roller 752 is configured to automatically release the sealing material and attach the sealing material to the conveying plate 720 (eg, the conveying plate bottom) according to instructions received from the controller, eg, at the beginning of each conveying cycle. The system also includes a cutting tool 754 for automatically cutting the sealing material at predefined points (eg, performing the cutting after transferring each layer of material to the working chamber, since the used sealing material already has holes and therefore cannot be use). In some cases, the cut used material is collected into a waste container and new sealing material is attached to the lower portion of the plate. In some embodiments, the automatic sealing tape roll 752 and the cutting tool 754 are positioned close to each other and are attached to the bottom distal end of the delivery plate 720 . In some cases, the sealing material may be made of thin nylon or other materials, such as PVC and LDPE having a thickness between 10 microns and 50 microns, and sized to seal the bottom 722 of the delivery plate and shape. For example, the conveying plate 720 may have a rectangular shape with a width of between 50 cm and 70 cm, and thus the sealing material may be of a compatible size for covering the bottom of the conveying plate 720 . The self-sealing belt roll 752 may be of any type known in the art including rotating drums. A non-limiting example of a suitable belt includes a motor attached to the shaft of the sealing roller and released rotationally according to the speed of movement of the plate.

According to some embodiments, the system 700 includes a plurality of hopper units and scanning units, such as the unit shown in FIG. 2C , located, for example, below the conveyor plate 720 . For example, system 700 may include three hopper units 713A, 713B, and 713C for supplying, for example, three different types of materials to be attached to surface 722 by suction. The system 700 also includes corresponding scanning units, eg three scanning units 740A, 740B and 740C, for emitting light beams to form holes in selective locations on the sealing surface according to a predefined image structure. The system 700 also includes a cleaning unit 717 located, for example, below the left distal end of the transport plate 720, for removing particles from the transport plate from previous printing cycles.

FIG. 8 shows a schematic diagram of a cross-section of the delivery plate 720 of FIG. 7, according to an embodiment. The delivery unit 820 may include an upper sealing layer 860, a cavity 845 having a low air pressure relative to outside air pressure, a bottom layer including a plurality of holes 814, and a sealing layer including a sealing material 850 for covering the bottom layer (eg, and holes 814). According to some embodiments, the size of each hole 814 is smaller than the size of a single powder particle for blocking powder from entering cavity 845 , but allowing air to pass through hole 814 into cavity 845 . For example, in some cases, the diameter of a single powder particle may be in the range of 10 to 20 microns, so the diameter of each hole 814 should be less than 10 microns for preventing powder from entering the cavity 845 .

In some cases, the sealing layer may be made of a resilient material, such as rubber, and the bottom layer may be made of ceramic or other low friction material.

FIG. 9A shows a flowchart of a method 900 for conveying various materials using a vacuum method, according to an embodiment. 9B illustrates a schematic top view of the state of the delivery system 700 at each delivery step, according to an embodiment. At step 910, a vacuum seal chamber is created, eg, by connecting a transfer plate to a tube for drawing air from the seal chamber. At step 920, the transport plate is activated and moved to the working chamber, eg, in the direction of arrow 725. At step 930, a sealing material 850 (eg, nylon) is fastened, eg, to the bottom surface of the delivery plate. In some cases, as illustrated in Figure 9B Stage 1, the sealing material 850 is released from the automatic sealing belt roller 752 and secured to the delivery plate. At step 940, the sealing layer is perforated to form openings (eg, nylon holes) in the layer on the sealing surface according to a predefined image. In some cases, the apertures are formed by one or more scanners, such as by a laser source configured to emit a laser beam to selected areas on the sealing surface for forming an image on the surface. For example, as illustrated in Figure 9B Stage 2, the first hole 921 is formed at the bottom surface of the conveying plate by a scanner (eg, scanning unit 840A). At step 950, powder is drawn into the perforated sealing material, thereby forming a powder image. Specifically, as illustrated in Figure 9B Stage 3, once the delivery plate passes the first hopper unit 813A, the first type of powder is drawn from the hopper unit to the holes 814 located at the bottom surface of the delivery plate. Since the pore size is smaller than the powder size, the powder remains on the surface of the plate, forming the image 921'. At step 960, the inhalation process is repeated for attaching the following types of powder to the delivery plate according to the predefined image. For example, as illustrated in stages 3-6 of Figure 9B, a second type of powder is drawn into aperture 931, forming a powder image 931'. At step 970, after all materials (eg, A, B, and C) have been gathered and attached by the conveying plates from the respective hopper units, the conveying plates are continuously moved towards the work vessel and positioned over the working chambers, thus attached to the conveying plates An image of the bottom portion of the powder is placed over the working chamber (eg, covering the working chamber). At step 980, the suction tube is disconnected and/or closed from the delivery plate, and thus, the powder falls from the delivery plate to the working chamber. At step 985, the transfer plate is moved back to the "home" position for transferring the next powder layer. In addition, the surface of the conveying plate is cleaned by the cleaning unit 717, for example when the conveying plate is moved back to the "home" position. At step 990, a binary decision may be made regarding the index number of the allocated layer. If it is the last layer (eg, all 3D object layers are transferred and fused at the studio), the printing process is complete and the carrier lift is raised back to the maximum upper level of the studio 490. If not the last layer, the process continues and the receiving layer moves back to step 920 for collecting and transporting the next layer.

Compression method and system for forming 3D objects

In recent years, various methods and systems for three-dimensional object production of hard metals such as tungsten carbide have become available. One of the most common methods used for the 3D metal production process is molding. The method includes compressing the metal in powder form into a dense metal powder form and sintering the compressed form to produce a 3D metal object. The compression step is required to avoid hollow regions and cross-sections in the fully formed product after the sintering stage.

Specifically, powders, such as hard metals or carbides or titanium, are formed into desired shapes by pressing such powders between a pair of press dies or punch and die assemblies. The molds used in such pressing methods require a high degree of dimensional accuracy.

10 is a cross-sectional view of a molding system 1000 according to the prior art. The system includes a die cavity 1010 for receiving metal dispensed in powder form from a hopper 1040, a top punch 1020 and a bottom press 1030 for pressing the dispensed powder. In operation, metal powder is fed into the mold cavity 1010 through a hopper 1040 (eg, a shoe hopper) until the mold cavity 1110 is filled. At the next step, the top punch 1020 compresses the powder down to form a dense powder form. Thereafter, the top punch is lifted out of the die cavity 1010 while the bottom punch is moved upwards for releasing the compacted powder from the die cavity. Therefore, each compacted powder is transferred to the sintering process for completing the curing process. The delivery process is repeated for each received metal powder.

Existing compression methods and systems can be suboptimal in at least some respects. Existing 3D compression methods involve fixing a cavity model specific to the requested product for generating the requested 3D object, therefore, a circular shape model may obviously not be able to be used to form a 3D square shape object.

Furthermore, due to the difficulty of effectively placing powders in several die casts, existing compression methods and systems typically provide a single object at each compression operation cycle, whereas the present method and system can be used in a single compression cycle Simultaneously compress multiple independent 3D objects.

11 is a schematic diagram illustrating a system 1100 for generating one or more 3D objects, according to an embodiment. System 1100 presents all of the elements of the aforementioned system 260 of FIG. 2C, but instead of energy unit 295, system 1100 includes a compression system 1120 for forming a 3D dense powder object. Advantageously, the compression system does not require a predefined model for generating the 3D object, and the 3D object can be formed by constructing the three-dimensional object using at least two materials from computer data describing the 3D object and assigning successive layers of uncured material to the compression system object. Furthermore, the systems and methods of the present invention can generate 3D objects that include complex geometries that may not be fabricated according to prior art methods due to geometric limitations of extrusion. For example, a 3D object may include lumen spaces that are not accessible from the outside. These geometries can be very important for heat dissipation of hard metal cutting tools, such as cutters. Specifically, thermal stress is the most important failure factor in these tools. In addition, most of the corrosion of these knives is caused by heating the knives due to friction during cutting, and the use of special shapes including internal lines for transporting liquid coolant can reduce heating of the knives and thus extend the length of time in use.

According to some embodiments, system 1100 includes a delivery system, such as electrophotographic delivery system 1110 , configured to transfer a continuous layer (eg, in powder form) comprising one or more uncured materials to working chamber 1119 . The working chamber 1119 may include a compression system 1120 including a container 1132 having a cavity, a receiving surface 1125 for receiving successive layers (eg, in the form of powder), and for compressing each dispensed powder layer to form a dense powder layer The top press 1130.

In some cases, the size of the top press should be a bit larger than the work surface so that the top press can compress the entire layer in one practice. Movement and power of the top press can be accomplished, for example, by a mechanical motor or by pressure generated by hydraulic pistons.

According to some embodiments, the conveying system 1100 includes a plurality of rollers for dispensing various types of materials. For example, the system 1100 may include two rollers 1114A, 1114B for dispensing two types of materials to an electrostatic transfer plate 1132 that is configured to receive a variety of materials and transfer the materials layer by layer to Studio 1120. For example, a first roller 1114A may dispense a first type of material 1121 including carbide (eg, in powder form) for forming the shape of a 3D carbide object, such as a carbide cutting tool, and a second roller , which is used to dispense a second type of material (eg, in powder form) that may not be processed by the sintering device, such as granular material. The particulate material may include finely divided rock and mineral particles (such as sand or titanium nitrite) used as a shell or outer support for the first material 1121 for processing.

In some cases, the second material has a higher sintering temperature than the first material, and thus does not melt at the sintering temperature of the first material, and remains in powder form.

The continuous layer comprising the two uncured materials can be transferred to the work surface 1125 by the transfer plate 1132 and can be compressed by the top press to form a dense powder. The compressed material can be transferred to a sintering system or locally heated at the working chamber 1119 using a heating device that hardens the first material (eg carbide) while keeping the second material in powder form and thus allows extraction Prepared 3D objects.

12 illustrates a flow diagram of a method 1200 for delivering at least two materials in powder form to a compression system and generating one or more 3D objects, according to an embodiment. At step 1210, a first powder material is applied to the delivery plate, and at step 1220, a second material is applied to the delivery plate, thereby forming a layer comprising two uncured layers. According to an embodiment, at least one material (eg, the first material) is an unsintered material, such as a granular material having a sufficiently high melting temperature that it is not subject to formation from other materials (eg, non-granular materials) for use in 3D objects effect of the sintering process of the shell or frame. For example, the sintering temperature of the granular material should be higher than the sintering temperature of other (eg, second) materials. The two materials are dispensed to the transport plate according to data received from one or more processors (eg, computer-controlled processors), such as including information in the form of, eg, one or more images of sliced layers of the 3D object. The material may be transported using electrostatic methods as illustrated in Figures 2A-2C or according to other methods and systems for transporting at least two materials to a compression system as illustrated in Figures 5-8. At step 1230, a layer comprising both materials is dispensed from the transport plate to the working chamber (eg, to a work surface). At step 1240, the allocated layers are compressed. For example, the top press 1120 moves downward toward the work surface in the direction of arrow 1131 and compresses the dispensed layer. At step 1250, a binary decision may be made regarding the index number of the allocated layer. If it is the last layer (eg, all 3D object layers are transferred to the studio and compressed), the compressed layer at step 1260 is sintered, eg, using a sintering furnace, to be formed from one material (eg, a carbide material) A 3D object consisting of a solid block. If it is not the last layer, the process continues at step 1210 to deliver the next layer.

In some cases, the sintering of the powder layer includes sintering the first powder material and the second powder material at a sintering temperature of the first powder material.

It is emphasized that the use of two materials is only an example of possible 3D objects that can be used. It is also possible to use 3D objects that include more than two materials, one of which is a granular material.

It is also emphasized that the components of the delivery system as illustrated in Figures 2, 3, 5-12 are ideally held within a closable housing (not shown) that protects the environment from Light is transmitted to the components of the system during operation.

Although described herein as a roller, the photoconductor roller may alternatively be a roller, belt assembly, or other rotatable assembly.

The present disclosure provides a computer control system programmed to implement the methods of the present disclosure. Figure 13 schematically illustrates an example of a computer system suitable for use in conjunction with methods and apparatus according to some embodiments of the present disclosure.

Computer system 1301 may be, for example, host computer 282, or may include the processor or controller of FIG. 2 . Computer system 1301 can process various aspects of the information of the present disclosure, such as, for example, questions and answers, responses, statistical analysis. Computer system 1301 may be a user's electronic device or a computer system that is remotely located relative to the electronic device. The electronic device may be a mobile electronic device.

Computer system 1301 includes a central processing unit (CPU, also referred to herein as "processor" and "computer processor") 1305, which may be a single-core processor or a multi-core processor, or multiple processors for parallel processing . The computer system 1301 also includes a memory or memory location 1310 (eg, random access memory, read only memory, flash memory), an electronic storage unit 1315 (eg, a hard disk), for communicating with one or more other systems. Communication interface 1320 (eg, a network adapter) and peripheral devices 1325, such as cache memory, other memory, data storage, and/or electronic display adapters. The memory 1310, storage unit 1315, interface 1320, and peripherals 1325 communicate with the CPU 1305 through a communication bus (solid line) such as a motherboard. The storage unit 1315 may be a data storage unit (or data repository) for storing data. Computer system 1301 may be operably coupled to a computer network (“network”) 1330 with the aid of communication interface 1320 . Network 1330 may be the Internet, an intranet and/or extranet, or an intranet and/or extranet in communication with the Internet. Network 1330 is, in some cases, a telecommunications and/or data network. Network 1330 may include one or more computer servers, which may enable distributed computing, such as cloud computing. Network 1330 may in some cases implement a peer-to-peer network with the aid of computer system 1301, which may enable devices coupled to computer system 1301 to function as clients or servers.

The CPU 1305 may execute a series of machine-readable instructions, which may be embodied in a program or software. Instructions may be stored in a memory location, such as memory 1310 . These instructions may be directed to the CPU 1305, which may then program or otherwise configure the CPU 1305 to implement the methods of the present disclosure. Examples of operations performed by the CPU 1305 may include fetch, decode, execute, and write back.

CPU 1305 may be part of a circuit, such as an integrated circuit. One or more other components of system 1301 may be included in the circuit. In some cases, the circuit is an application specific integrated circuit (ASIC).

The storage unit 1315 may store files such as drivers, libraries, and saved programs. The storage unit 1315 may store user data, such as user preferences and user programs. In some cases, computer system 1301 may include one or more additional data storage units external to computer system 1301, such as on a remote server in communication with computer system 1301 via an intranet or the Internet.

iPad、

Galaxy Tab)、电话、智能电话(例如，

iPhone、支持安卓的设备、

)、个人数字助理、可穿戴医疗设备(例如，Fitbits)、或医疗设备监视器(例如，癫痫发作监视器(seizure monitors))。用户可以利用网络1330访问计算机系统1301。Computer system 1301 may communicate with one or more remote computer systems through network 1330 . For example, computer system 1301 may communicate with a remote computer system of a user (eg, a parent). Examples of remote computer systems and mobile communication devices include personal computers (eg, portable PCs), slate or tablet PCs (

iPad,

Galaxy Tab), phones, smartphones (e.g.,

iPhone, Android-enabled devices,

), personal digital assistants, wearable medical devices (eg, Fitbits), or medical device monitors (eg, seizure monitors). A user may access computer system 1301 using network 1330 .

The methods as described herein may be implemented by machine (eg, computer processor) executable code stored on an electronic storage location of computer system 1301, such as, for example, on memory 1310 or electronic storage unit 1315. Machine executable code or machine readable code may be provided in the form of software. During use, the code may be executed by the processor 1305 . In some cases, code may be retrieved from storage unit 2185 and stored on memory 1310 for ready access by processor 1305. In some cases, electronic storage unit 1315 may be excluded, and machine-executable instructions stored on memory 1310 .

The code may be precompiled and configured for use with a machine having a processor adapted to execute the code, or may be compiled at runtime. The code may be supplied in a programming language, which may be selected to enable the code to be executed in a precompiled or compiled manner.

Aspects of the systems and methods provided herein, such as computer system 401, may be embodied in programming. Aspects of the technology may be considered "products" or "articles of manufacture," typically in the form of machine (or processor) executable code and/or associated data that is carried on or embodied in one type of machine-readable medium. Machine executable code may be stored on an electronic storage unit, such as a memory (eg, read only memory, random access memory, flash memory) or a hard disk. A "storage" type medium may include any or all tangible storage of a computer, processor, etc., or their associated modules, such as various semiconductor memories, tape drives, disk drives, etc., which can provide non-transitory memory for software programming at any time Sexual storage. All or part of the software may sometimes communicate over the Internet or various other telecommunications networks. For example, such communication may enable the loading of software from one computer or processor into another computer or processor, eg, from a management server or host computer into a computer platform of an application server. Thus, another type of medium that can carry software elements includes optical, electrical, and electromagnetic waves, such as through wired and optical landline networks and between local devices over various air-links used on the physical interface. Physical elements that carry such waves, such as wired or wireless links, optical links, etc., may also be considered software-carrying media. As used herein, unless limited to non-transitory, tangible "storage" media, terms such as computer or machine "readable medium" refer to any medium that participates in providing instructions to a processor for execution.

Accordingly, a machine-readable medium, such as computer-executable code, may take many forms, including, but not limited to, tangible storage media, carrier wave media, or physical transmission media. Non-volatile storage media include, for example, optical or magnetic disks, such as any storage device such as in any computer or the like that may be used to implement a database or the like, as shown in the figures. Volatile storage media include dynamic memory, such as the main memory of such a computer platform. Tangible transmission media include coaxial cables; copper wire and fiber optics, including the wires that comprise buses within computer systems. Carrier-wave transmission media may take the form of electrical or electromagnetic signals, or acoustic or light waves, such as those generated during radio frequency (RF) and infrared (IR) data communications. Thus, common forms of computer readable media include, for example: floppy disk, flexible disk, hard disk, magnetic tape, any other magnetic medium, CD-ROM, DVD or DVD-ROM, any other optical medium, punched card tape , any other physical storage medium having a pattern of holes, RAM, ROM, PROM and EPROM, FLASH-EPROM, any other memory chip or cartridge, carrier waves that transmit data or instructions, cables or links that transmit such carrier waves, or a computer may Any other medium from which programming code and/or data is read. Many of these forms of computer-readable media can be involved in carrying one or more sequences of one or more instructions to a processor for execution.

The computer system 1301 may include or be in communication with an electronic display 1335 that includes a user interface (UI) 1340 for providing, for example, questions and answers, analysis results, suggestions. Examples of UI include, but are not limited to, graphical user interfaces (GUIs) and web-based user interfaces.

In further embodiments, the processing unit of the 3D printing system may be a digital processing device that includes one or more hardware central processing units (CPUs) that perform the functions of the device. In still further embodiments, the digital processing device further includes an operating system configured to execute the executable instructions. In some embodiments, the digital processing device is optionally connected to a computer network. In further embodiments, the digital processing device is optionally connected to the Internet so that it accesses the World Wide Web. In yet other embodiments, the digital processing device is optionally connected to a cloud computing infrastructure. In other embodiments, the digital processing device is optionally connected to an intranet. In other embodiments, the digital processing device is optionally connected to the data storage device.

According to the description herein, suitable digital processing devices include, by way of non-limiting example, server computers, desktop computers, laptop computers, notebook computers, small notebook computers, netbook computers, netpad computers, set-top box computers, Handheld computers, Internet appliances, mobile smart phones, tablet computers, personal digital assistants, video game consoles and vehicles. Those skilled in the art will recognize that many smartphones are suitable for use in the systems described herein. Those skilled in the art will also recognize that selected televisions with optional computer network connectivity are suitable for use in the systems described herein. Suitable tablet computers include those with manual, tablet and convertible configurations known to those skilled in the art.

Linux、

Mac OS X

Windows

和

本领域技术人员将认识到，合适的个人计算机操作系统包括(通过非限制性示例)

Mac OS

和类似UNIX的操作系统，诸如

在一些实施方案中，操作系统通过云计算提供。本领域技术人员还将认识到，合适的移动智能手机操作系统包括(通过非限制性示例)

OS、

Research In

BlackBerry

Windows

OS、

Windows

OS、

和

In some embodiments, the digital processing device includes an operating system configured to execute executable instructions. An operating system is, for example, software, including programs and data, that can manage the hardware of a device and provide services for executing application programs. Those skilled in the art will recognize that suitable server operating systems may include (by way of non-limiting example) FreeBSD, OpenBSD,

Linux,

Mac OS X

Windows

and

Those skilled in the art will recognize that suitable personal computer operating systems include (by way of non-limiting example)

Mac OS

and UNIX-like operating systems such as

In some embodiments, the operating system is provided through cloud computing. Those skilled in the art will also recognize that suitable mobile smartphone operating systems include (by way of non-limiting example)

OS,

Research In

BlackBerry

Windows

OS,

Windows

OS,

and

In some embodiments, the device includes a storage and/or memory device. A storage and/or memory device is one or more physical devices used to store data or programs on a temporary or permanent basis. In some embodiments, the device is volatile memory and requires power to maintain stored information. In some embodiments, the device is non-volatile memory and retains stored information when the digital processing device is not powered. In additional embodiments, the non-volatile memory includes flash memory. In some implementations, the non-volatile memory includes dynamic random access memory (DRAM). In some implementations, the nonvolatile memory includes ferroelectric random access memory (FRAM). In some implementations, the non-volatile memory includes phase change random access memory (PRAM). In other embodiments, the device is a storage device including, by way of non-limiting example, CD-ROMs, DVDs, flash memory devices, magnetic disk drives, tape drives, optical disk drives, and cloud computing-based storage. In further embodiments, the storage and/or memory device is a combination of devices such as those disclosed herein.

In some embodiments, the digital processing device includes a display that transmits visual information to a user. In some embodiments, the display is a cathode ray tube (CRT). In some embodiments, the display is a liquid crystal display (LCD). In further embodiments, the display is a thin film transistor liquid crystal display (TFT-LCD). In some embodiments, the display is an organic light emitting diode (OLED) display. In various additional embodiments, the OLED display is a passive matrix OLED (PMOLED) or an active matrix OLED (AMOLED) display. In some embodiments, the display is a plasma display. In other embodiments, the display is a video projector. In still further embodiments, the display is a combination of devices such as those disclosed herein.

In some embodiments, the digital processing device includes an input device that receives information from a user. In some embodiments, the input device is a keyboard. In some embodiments, the input device is a pointing device including, by way of non-limiting example, a mouse, trackball, trackpad, joystick, game controller, or stylus. In some embodiments, the input device is a touch screen or a multi-touch screen. In other embodiments, the input device is a microphone to capture speech or other sound input. In other embodiments, the input device is a camera to capture motion or visual input. In still further embodiments, the input device is a combination of devices such as those disclosed herein.

In some embodiments, the systems disclosed herein include one or more non-transitory computer-readable storage media encoded with a program, the program including data generated by an optionally networked digital processing device instructions executable by the operating system. In further embodiments, the computer-readable storage medium is a tangible component of a digital processing device. In still further embodiments, the computer-readable storage medium is optionally removable from the digital processing device.

In some embodiments, computer readable storage media include, by way of non-limiting example, CD-ROMs, DVDs, flash memory devices, solid state memory, magnetic disk drives, tape drives, optical drives, cloud computing systems and services, and the like. In some cases, the programs and instructions are encoded on the medium permanently, substantially permanently, semi-permanently or non-transitory. In some embodiments, the systems disclosed herein include at least one computer program or use thereof. A computer program includes a sequence of instructions executable in the CPU of a digital processing device, the sequence of instructions being written to perform specified tasks. Computer-readable instructions may be implemented as program modules that perform particular tasks or implement particular abstract data types, such as functions, objects, application programming interfaces (APIs), data structures, and the like. From the disclosure provided herein, those skilled in the art will recognize that computer programs can be written in various versions in various languages.

The functionality of the computer readable instructions may be combined or distributed as desired in various environments. In some embodiments, the computer program includes a sequence of instructions. In some embodiments, the computer program includes multiple sequences of instructions. In some embodiments, the computer program is provided from one location. In other embodiments, the computer program is provided from multiple locations. In various embodiments, a computer program includes one or more software modules. In various embodiments, the computer program includes, in part or in whole, one or more web applications, one or more mobile applications, one or more stand-alone applications, one or more web browser plug-ins, extensions, loading Macro (add-in) or add-in (add-on) or a combination thereof.

In some embodiments, the computer program includes a mobile application provided to a mobile digital processing device. In some embodiments, the mobile application is provided to the mobile digital processing device when it is manufactured. In other embodiments, the mobile application is provided to the mobile digital processing device via the computer network described herein.

In some embodiments, the systems disclosed herein include software, server and/or database modules, or uses thereof. In view of the disclosure provided herein, software modules are created by techniques known to those skilled in the art using machines, software and languages known in the art. The software modules disclosed herein are implemented in a variety of ways. In various embodiments, software modules include files, code segments, programming objects, programming constructs, or combinations thereof. In further various embodiments, a software module includes multiple files, multiple code segments, multiple programming objects, multiple programming constructs, or combinations thereof. In various embodiments, the one or more software modules include, by way of non-limiting example, web applications, mobile applications, and stand-alone applications. In some embodiments, the software modules are in a computer program or application. In other embodiments, the software modules are in more than one computer program or application. In some embodiments, the software modules are hosted on one machine. In other embodiments, the software modules are hosted on more than one machine. In further embodiments, the software modules are hosted on a cloud computing platform. In some embodiments, software modules are hosted on one or more machines in one location. In other embodiments, the software modules are hosted on one or more machines in more than one location.

In some embodiments, the systems disclosed herein include one or more databases or uses thereof. In view of the disclosure provided herein, those skilled in the art will recognize that many databases are suitable for storing and retrieving information as described herein. In various embodiments, suitable databases include, by way of non-limiting example, relational databases, non-relational databases, object-oriented databases, object databases, entity-relationship model databases, relational databases, and XML databases. In some embodiments, the database is Internet based. In other embodiments, the database is web-based. In yet other embodiments, the database is cloud computing based. In other embodiments, the database is based on one or more local computer storage devices.

In the above description, an embodiment is an example or implementation of the invention. The different appearances of "one embodiment," "an embodiment," or "some embodiments" are not necessarily all referring to the same embodiments.

Although various features of the invention may be described in the context of a single embodiment, these features can also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention may also be practiced in a single embodiment.

Reference in this specification to "some embodiments," "an embodiment," "one embodiment," or "other embodiments" means that a particular feature, structure, or characteristic described in connection with an embodiment is included within the scope of the present invention. In at least some embodiments, but not necessarily all embodiments.

It is to be understood that the phraseology and terminology used herein should not be regarded as limiting and for the purpose of description only.

The principles and uses of the teachings of the present invention may be better understood with reference to the accompanying description, drawings and examples.

It should be understood that the details set forth herein do not limit the application of the invention.

Furthermore, it should be understood that the present invention may be embodied or practiced in various ways and that the present invention may be practiced in embodiments other than those outlined in the foregoing description.

It should be understood that the terms "comprising", "comprising", "consisting of" and their grammatical variants do not exclude the addition of one or more components, features, steps or integers or groups thereof, and that these terms should be construed as specifying components, features , step or whole.

If the specification or claim refers to "additional" elements, that does not preclude there being more than one of the additional elements.

It will be understood that, where the claim or specification refers to "a (a)" or "an (an)" element, such reference should not be construed as referring to only one of that element. It is to be understood that where the specification states that a component, feature, structure or characteristic "may", "might", "can" or "could" be included, the particular component , features, structures or characteristics need not be included. Where applicable, although state diagrams, flow diagrams, or both may be used to describe embodiments, the invention is not limited to these diagrams or the corresponding description. For example, flow need not move through each illustrated block or state, or in exactly the same order as illustrated and described. The methods of the present invention may be accomplished by performing or completing selected steps or tasks manually, automatically, or a combination thereof.

The descriptions, examples, methods and materials presented in the claims and specification are not to be interpreted as limiting, but merely illustrative. Technical and scientific terms used herein have the meanings as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. The present invention can be implemented in the testing or practice using methods and materials equivalent or similar to those described herein.

While this invention has been described with reference to a limited number of embodiments, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of some preferred embodiments. Other possible variations, modifications and applications are also within the scope of the present invention. Therefore, the scope of the present invention should not be limited by what has been described so far, but by the appended claims and their legal equivalents.

All publications, patents and patent applications mentioned in this specification are herein incorporated by reference in their entirety into the specification to the same extent as if each publication, patent or patent application was specifically and individually indicated to be incorporated by reference herein . In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting. The methods and systems of the present disclosure may be implemented by one or more algorithms and instructions provided with one or more processors as disclosed herein. The algorithms may be implemented in software when executed by the central processing unit 2305. The algorithm can be, for example, random forests, graphical models, support vector machines, or others.

Although the above steps illustrate a method according to an example system, those of ordinary skill in the art will recognize many variations based on the teachings described herein. Steps can be done in a different order. Steps can be added or deleted. Some of the steps may include sub-steps. Many steps can be repeated as often as it benefits the platform.

Each of the examples as described herein may be combined with one or more other examples. Furthermore, one or more components of one or more examples may be combined with other examples.

Although the detailed description contains many details, these should not be construed as limiting the scope of the disclosure, but merely as illustrating various examples and aspects of the disclosure. It should be understood that the scope of the present disclosure includes other embodiments not discussed in detail above. Various other modifications, changes that will be apparent to those skilled in the art may be made in the arrangement, operation and details of the methods and apparatus of the present disclosure provided herein without departing from the spirit and scope of the invention as described herein and change.

While preferred embodiments of the present disclosure have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will be apparent to those skilled in the art without departing from the scope of this disclosure. It should be understood that various alternatives to the embodiments of the disclosure described herein may be employed without departing from the scope of the present invention. Accordingly, the scope of the present invention should be defined only by the appended claims and their equivalents.

Claims (20)

1. A delivery system for delivering multiple layers of powder to a three-dimensional (3D) printing system for printing at least one 3D object, the delivery system comprising: a rotatable drum having a circular photosensitive outer surface; a hopper unit including a container for storing the powder, wherein the hopper unit is configured to dispense the powder onto the photosensitive outer surface of the rotatable drum; a conveying unit comprising a movable conveying plate having an electrically conductive outer surface, the conveying unit connectable to an engine for moving the conveying plate to a studio of the 3D printing system; one or more charging electrodes configured to charge the rotatable drum; a charging unit configured to charge the transport plate; and Wherein, the movable conveying unit is further configured to: electrically and sequentially attracting the plurality of layers from the outer surface of the rotatable drum to the conductive outer surface thereof; and The attracted layers are transferred to the working chamber by electrically repelling the attracted layers into the working chamber. 2. The system of claim 1, wherein the conductive outer surface is coated with one or more layers of insulating material. 3. The system of claim 1, wherein the powder comprises a non-conductive powder material or a conductive powder material. 4. The system of claim 1, wherein the hopper unit comprises one or more layers of insulating material. 5. The system of claim 1, wherein the rotatable drum includes a cleaning unit configured to clean the photosensitive outer surface of the rotatable drum. 6. The system of claim 1, wherein the conveying unit comprises a cleaning unit configured to clean a surface of the conveying plate. 7. The system of claim 1 comprising: a plurality of rotatable drums having circular photosensitive outer surfaces for respectively receiving the plurality of layers, wherein each of the plurality of rotatable drums comprises: the hopper units, wherein each hopper unit includes the container for storing the powder or one or more other types of powder; a cleaning unit configured to clean the photosensitive outer surfaces, respectively; one or more charging electrodes configured to apply an electrostatic charge to each respective rotatable drum of the plurality of rotatable drums; Energy scanning units, wherein each energy unit includes an energy source configured to selectively emit a beam of light towards a corresponding photosensitive outer surface for causing all of the at least one 3D object to Said photosensitive outer surface discharge; and wherein the movable conveying plate is configured to successively attract and electrically attract the plurality of layers from the plurality of rotatable drums to form a powder layer at the outer surface of the plate, and by applying the powder layer Electrorepelling into the working chamber transfers the powder layer to the working chamber in a layer-by-layer fashion. 8. The system of claim 7, wherein the studio comprises: a work surface configured to receive the plurality of layers and to be stepped down; and an energy head for melting the plurality of layers. 9. The system of claim 8, wherein the energy head is a laser head configured to model CAD cross-sectional data of a selected cross-sectional area of a model of the 3D object such that each A focused laser beam is applied to a given area of each of the plurality of layers corresponding to the selected cross-sectional area of the model in such a manner that each layer is secured to the layer below. 10. The system of claim 7, wherein the 3D printing system is a compression system. 11. The system of claim 10, wherein the compression system comprises: a container having a cavity; a receiving surface for receiving a plurality of layers from the transport plate; and A top press for compressing the multiple layers received and forming a dense powder layer. 12. The system of claim 11, wherein the dense powder layer is sintered. 13. The system of claim 12, wherein one of the dense powder layers includes a material that may not be sintered. 14. A method for delivering multiple layers of powder to a 3D printing system for generating one or more 3D objects, the method comprising: rotating at least one drum having a photosensitive surface; charging the at least one rotating drum for receiving the plurality of layers at the photosensitive surface from a hopper unit; moving a conveying unit tangentially relative to the at least one drum to the working chamber, wherein the conveying unit includes a movable conveying plate having a flat conductive outer surface; charging the transport plate for successively attracting the plurality of layers from the photosensitive surface of the at least one roller; Once the transport plate is above or near the working chamber, the electrical polarity of the transport plate is switched for repelling the layers into the working chamber. 15. The method of claim 14, comprising melting the repelled plurality of layers by an energy cell for use in creating the one or more 3D objects. 16. The method of claim 14, comprising compressing each of the repelling plurality of layers. 17. The method of claim 16, comprising sintering the compressed plurality of layers. 18. The method of claim 16, wherein the plurality of layers comprises a first type of powder material and a second type of powder material, wherein the second type of powder material has a higher density than the first type of powder material. higher sintering temperature for powder materials. 19. The method of claim 14 including moving the conveyor unit at a rate that is synchronous with the speed of the rotatable drum. 20. A delivery system for delivering multiple layers of powder for printing at least one 3D object, the delivery system comprising: a plurality of rotatable drums, wherein each rotatable drum of the plurality of rotatable drums has a photosensitive outer surface for receiving the plurality of layers, respectively, and wherein each of the plurality of rotatable drums The rotatable drums include: a hopper unit, wherein the hopper unit includes a container for storing one or more materials in powder form; a cleaning unit configured to clean respective photosensitive outer surfaces of the plurality of rotatable drums; one or more charging electrodes configured to apply electrostatic charges to the rotatable drum, respectively; a scanning energy unit, wherein the scanning energy unit includes an energy source configured to selectively emit light beams toward respective photosensitive outer surfaces of the plurality of rotatable drums for use in accordance with the at least one A predefined image structure of the 3D object discharges the photosensitive outer surface; a conveying unit comprising a movable conveying plate having an electrically conductive outer surface, the conveying unit connectable to an engine for moving the conveying plate to a studio of the 3D printing system; a charging unit configured to charge the transport plate; and wherein the movable conveying plate is configured to successively attract and electrically attract the plurality of layers from the plurality of rotatable drums to form layers of the plurality of powder materials at the outer surface of the plate, and by transferring the material The layers are electrically repelled into the working chamber to transfer the layers of the plurality of powder materials to the working chamber in a layer-by-layer fashion.

Images